Biomedical subjects
Publications and source records attributed to R Bonita.
Public health represents society's organised and publicly supported efforts to improve the health status of the entire population; its focus is on the reduction of health inequalities by optimising the underlying determinants of health and preventing disease. But public health is under threat and needs to be strengthened so that it is at the centre of human endeavour--locally, nationally, and worldwide.
AIM: To describe the distribution of the major cardiovascular risk factors among older men and women in the Auckland region, New Zealand. METHODS: Means and prevalences of the major cardiovascular risk factors were estimated for non-Maori, non-Pacific Islands men and women in the age groups 65-74 and 75-84 years using data from the 1993-4 survey of the University of Auckland Heart and Health Study, a cross-sectional, population-based study of cardiovascular risk factors. RESULTS: 996 people aged 65-84 years participated, with men and women and the two ten-year age groups almost equally represented. Fewer than half engaged in regular leisure time physical activity; around 35% were overweight (BMI 25-30) and 10% were obese (BMI > 30). Total mean cholesterol levels were higher in women and 46% of women had a cholesterol level > or = 6.5 mmol/L compared with only 17% of men. However, total cholesterol:HDL ratios were higher among men. Age and sex differences in blood pressure were small. Around 50% had raised blood pressure (BP > 150/90) or were currently on antihypertensive medication; only 8% smoked; around 6% were diabetic. Almost 8% had three or all of four major modifiable cardiovascular risk factors (elevated blood pressure, total cholesterol:HDL ratio > or = 6.5, current smoking and physical inactivity). CONCLUSIONS: These results are broadly comparable to those from other Western populations. Differences between 65-74 and 75-84 year age groups are few but important differences in cholesterol, smoking and physical activity between older men and women are noted. These findings indicate that there is considerable potential for prevention of cardiovascular disease among older people.
Comparison of stroke incidence and case fatality in different parts of the world provides information that may lead to a better understanding of the disease. In this report we have investigated these two aspects in two large populations, one in Auckland, New Zealand, and the other in Copenhagen, Denmark (the Copenhagen City Heart Study, CCHS). Incidence rates of stroke are higher for men than women in both studies. The stroke incidence rate ratios between Auckland men and CCHS men are significantly different in most age groups, whereas in women the incidence rates differ only in one age group. The age- and sex-adjusted incidence rates are higher in the CCHS for both men and women as compared to the Auckland Stroke Study. The age-adjusted incidence rate ratio is higher for men than women in both studies: 1.29 in the Auckland Stroke Study and 1.54 in the CCHS. The 28-day case fatality is also higher in the CCHS than in Auckland and is higher for women than men in both studies. The incidence rate of stroke and the 28-day case fatality is higher in the CCHS as compared to the Auckland Stroke Study in both men and women. A very high proportion of smokers in CCHS may explain some of the differences in incidence rates in the two populations.
BACKGROUND AND PURPOSE: As with total stroke, mortality rates from subarachnoid hemorrhage (SAH) have declined in New Zealand since the mid-1970s. Data from the Auckland Region Stroke studies allow an understanding of reasons for the change, as SAH incidence and 28-day case fatality rates were measured as part of population-based stroke registers. METHODS: National death registrations were used to describe the trends in mortality rates from SAH (International Classification of Diseases [ICD] code 430) among men and women in New Zealand. Changes in incidence and case fatality rates were determined from 2 large-scale population-based stroke registries carried out in 1981-1983 and 10 years later in Auckland. Similar methodology and case ascertainment techniques were used in both studies. RESULTS: The mortality rates from SAH declined in both men and women after the mid-1970s. The mortality rate remained higher among women than men. The incidence of SAH was lower in 1991-1993 (11.3 per 100,000) compared with 1981-1983 (14.6 per 100,000). In the younger age groups, the decrease was mostly due to a lower incidence among men, whereas in the older age groups women older than 65 years had a lower incidence. There was no consistent change in case fatality rates between the 2 periods in either men or women. CONCLUSIONS: Mortality rates from SAH have decreased in both men and women. This decrease may be explained by a decrease in the incidence of SAH, because case fatality rates showed no change.
BACKGROUND: Studies of acute stroke management in stroke units and tertiary referral hospitals may not accurately reflect practice within the population. Reliable information on the management of stroke within a population is sparse. AIMS: To compare clinical practice in acute stroke management in Auckland with guidelines for the management and treatment of stroke in other countries; to provide a baseline measure against which future changes in management can be evaluated. METHODS: All new stroke events in Auckland residents in 12 months were traced through multiple case finding sources. For each patient, a record of investigations and treatment during the first week of hospital admission was kept. RESULTS: One thousand eight hundred and three stroke events (including subarachnoid haemorrhages) occurred in 1761 patients in one year. Twenty-seven per cent of all events were managed outside hospital and 73% of the stroke events were treated in an acute hospital. Of the 1242 stroke events admitted to an acute hospital in the first week, only 6% were managed on the neurology and neurosurgery ward, 83% were managed by a general physician or geriatrician and 42% had computed tomography (CT). Of 376 validated ischaemic strokes, 44% were treated with aspirin and 12% with intravenous heparin. Of the 690 unspecified strokes (no CT or autopsy), 38% received aspirin and 0.5% heparin. The 28 day in-hospital case fatality for all stroke events admitted to an acute hospital during the first week was 25%. CONCLUSIONS: In Auckland, management of acute stroke differed from clinical guidelines in the high proportion of patients managed in the community, the low rate of neurological consultation, and the low frequency of CT scanning. Despite these deficiencies in management, the 28 day hospital case fatality in Auckland was similar to other comparable studies which had a high proportion of cases evaluated by a neurologist and CT.
BACKGROUND AND PURPOSE: To provide estimates of the prevalence of stroke and stroke-related disability for international comparisons and for planning purposes. METHODS: Estimates of prevalence were derived from two population-based studies conducted 10 years apart in Auckland, New Zealand. The first, carried out in 1981, included information on survival and stroke-related disability to 14 years after stroke, and the second, undertaken in 1991 to 1992, included this information up to 3 years after stroke. An actuarial model was developed that took into account changes in incidence, long-term survival, and population structure. RESULTS: Overall, it was estimated that 7491 people (3793 men and 3698 women) living in Auckland (total population 945,000) in 1991 had experienced a stroke at some stage in the past. This represents an age-standardized rate of 833 per 100,000 (991 per 100,000 in men and 706 per 100,000 in women) in the population aged 15 years and older. When only those who have made an incomplete recovery are considered, prevalence falls to 461 per 100,000. Of this group, one third (173 per 100,000 population 15 years and older) required assistance in at least one self-care activity. CONCLUSIONS: Usual estimates of stroke prevalence, which include all people who have ever experienced a stroke, may overestimate by almost twofold the prevalence of stroke-related disability, since many have either recovered or have no continuing dependency related to stroke. Overall prevalence does not provide information with sufficient precision for planning and purchasing ongoing services for stroke patients.
BACKGROUND AND PURPOSE: This study compares stroke incidence, 28-day case fatality, and hospital management for Maori, Pacific Islands people ("Pacific people"), and others (mostly Europeans) living in Auckland, New Zealand. METHODS: Data come from the Auckland Stroke Study, a population-based study that registered all stroke events occurring among Auckland residents aged 15 years or more during a 1-year period ending February 29, 1992. RESULTS: During the study year, 1803 stroke events were registered, including 82 (4.5%) in Maori, 113 (6.3%) in Pacific people, 1572 (87.2%) in Europeans, and 36 (2.0%) in others of Indian or Chinese origin. The mean +/- SD age of stroke patients was 55.0 +/- 16.0 years in Maori, 59.7 +/- 14.9 years in Pacific people, and 73.3 +/- 12.1 years in Europeans. Maori and Pacific people have significantly higher estimated relative risks of stroke compared with Europeans (OR, 1.34; 95% confidence interval [CI], 1.05 to 1.67 in Maori; and OR, 1.63; 95% CI, 1.33 to 1.98 in Pacific people). Maori and Pacific people also have higher estimated relative risks of death within 28 days of stroke compared with Europeans, especially men. CONCLUSIONS: This study indicates that there are important differences in stroke incidence rates and case fatality among the major ethnic groups in Auckland. The reasons for the higher incidence rates in Maori and Pacific people may be related to levels of risk factors, but this requires further investigation. Ongoing monitoring of stroke incidence and outcome should include separate reporting by ethnicity.
Faecal examination for Fasciola eggs which were preserved in 5% and 10% formalin and TAF solutions for 6 years was carried out using the Beads technique. The morphological characters and the distinctive yellowish color of Fasciola eggs were retained and appeared similar to those of fresh eggs. The mean egg recovery rate of eggs in TAF solution was significantly lower than the others (P < 0.01). The egg recovery rates from 5% and 10% formalin samples were 57.2% and 60.8%, respectively, and these values were similar to the value of 58.8% for fresh Fasciola eggs in cattle faeces. For Paramphistomum eggs, preserved with 5% formalin, the mean egg recovery rate was 64.7%. Fasciola eggs and Paramphistomum eggs were easily identified by their morphological characters in this experiment. The present data demonstrated that preservation with 5% formalin solution is an acceptable means of storing faecal samples for later examination of Fasciola and Paramphistomum eggs using the Beads technique and presumably by other fluke sedimentation methods.
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This article, based on a report (Women, aging and health: achieving health across the life span) prepared for the WHO Global Commission on Women's Health under the guidance of WHO's Aging and Health Programme, presents demographic data that clearly demonstrate the need for recognition of the health of aging women as a global issue of major public health concern. The authors show that, while female life expectancy at birth is significantly different in developed and developing countries (because of high infant and maternal mortality in the latter), these differences tend to decrease for women in developing countries who reach middle age. The authors review the various facets of the "gender transition" brought about by demographic and epidemiological transitions, drawing attention to contrasts between the situation in developing countries in Asia and Latin America and that in Eastern Europe, for example. The role of older women as care-givers is discussed, as is the likelihood of a future increase in the proportion of older women living alone in the developing world (a factor which renders them particularly vulnerable in many socioeconomic and health respects). Suggestions are made on methodologies for monitoring health trends in aging women, and on the role of WHO in this respect. A basic goal for global strategies relating to the health of older women is formulated: reduction of the inequities in life expectancy between developed and developing countries.
AIMS: To describe organisational characteristics of New Zealand general practice and to investigate inter-regional variations in these characteristics. METHODS: Data were collected by standardised questionnaires from general practitioners in Auckland, Waikato and Taranaki. The Waikato data were collected in July-August 1991 by postal survey, the Taranaki data were collected May-June 1992 by postal survey and the Auckland data were collected December 1990 to January 1991 by face-to-face interview. RESULTS: The response rates were Auckland 98% (167/171), Waikato 84% (185/220) and Taranaki 79% (79/100). There were significantly more overseas trained graduates in rural areas than in urban areas. Average practice size was 2.3 full time equivalent doctors, with each 100 doctors employing 71 nurses and 77 receptionists. The number of patients seen per week ranged from 109-141. Almost all (95%) general practitioners operated appointment systems. One in five general practitioners had patients in private hospitals, and more than half (58%) had patients in rest homes. At the time of interview, 29% of Auckland general practitioners used computers in their practices compared with over 50% in Waikato and Taranaki (p < 0.05). A smaller proportion of Auckland general practitioners had access to age/sex registers and fewer Auckland general practitioners had a recall system. Of Auckland general practitioners with recall systems, a greater proportion used them for mammograms, blood pressure and lipid measurements compared with elsewhere. CONCLUSIONS: There are some significant regional variations in the functional characteristics of general practice in New Zealand which should be taken into account when planning primary care services in different regions. Should budget holding and managed care be introduced, computerised practices will be required. This will have significant resource implications.
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BACKGROUND: Stroke registers are the preferred choice for determining incidence, case-fatality and severity of acute stroke in defined populations. This paper highlights some of the problems likely to be encountered in this endeavour by describing the experience of measuring acute stroke prospectively. METHODS: The Auckland Stroke Study is a community-based study among 945,000 residents of the Auckland region, New Zealand. Standard definitions and overlapping case-finding methods were used to identify all new acute stroke events occurring during the 12-month period ending 1 March 1992. Particular attention was directed at including non-fatal strokes managed outside hospital. The latter were identified by use of a cluster sample, a technique suitable for populations where residents have a personal primary health care physician. RESULTS: The comprehensive sources of referral to the study involved the review of 5736 records, less than one-third of which met the criteria for inclusion. The majority of included acute stroke events (n = 1803) were found through routinely available sources such as hospital admission records (63%) and death registrations (10%). The remainder (27%) were identified through intensive efforts at case-finding of stroke events managed outside hospital. The 1803 events were registered in 1761 people, 817 men and 944 women; for 587 (72%) men and 718 (76%) women, the stroke was the first ever experienced. CONCLUSIONS: While time-consuming, costly and demanding, there appears to be no easier alternative to a register to estimate incidence. This study demonstrates the importance of the use of comprehensive case-finding sources and suggests approaches to overcoming the difficulties in monitoring stroke incidence in large populations.
BACKGROUND AND PURPOSE: As part of the WHO MONICA Project (World Health Organization Monitoring Trends and Determinants in Cardiovascular Disease), mortality and incidence rates of acute stroke in 14 centers covering 21 populations from 11 countries were compared. METHODS: In this report, coverage and quality of the MONICA stroke registers were evaluated on five key indicators using data submitted to the MONICA Data Center. RESULTS: A low ratio of MONICA stroke register to routine statistics of stroke mortality and a low proportion of nonfatal out-of-hospital events were the most common biases; they indicate that identifications of fatal cases and/or case finding of nonfatal events occurring outside the hospital were inadequate in many MONICA centers. In 10 populations, the data quality analyses suggested that clarification of possible biases would be needed before these populations can be included in a comparative study. Data from the remaining 11 populations meet the data quality standards for multinational comparisons with respect to case ascertainment. CONCLUSIONS: These results show that multinational comparisons of stroke incidence involve considerable problems in developing and maintaining appropriate standards of data quality. However, after considerable efforts to ensure quality, comparisons of stroke data within the MONICA Project are possible among a large number of the MONICA populations. Our observations also indicate that results from multinational comparisons of stroke mortality based on routine statistics must be interpreted with caution.
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BACKGROUND AND PURPOSE: We undertook to examine the usefulness for epidemiological studies of two well-known validated clinical scoring methods, the Guys' Hospital Stroke score and the Siriraj Hospital Stroke score, to classify strokes into the two main types, hemorrhagic and ischemic, in epidemiological studies. METHODS: Patients from a population-based stroke register who received either a CT scan or an autopsy were retrospectively scored using the two clinical scoring methods. The scores were then compared with the CT scan and autopsy results to determine the sensitivity, specificity, and positive predictive value for intracranial hemorrhage (primary intracerebral and subarachnoid hemorrhage) and ischemic stroke. RESULTS: Over a 12-month period, 554 patients from a population-based study underwent CT scanning. Films or autopsy reports were available for 521 patients, and of these, sufficient clinical information to calculate the Guys' Hospital Stroke score and the Siriraj Hospital Stroke score was available for 464 and 475 patients, respectively. For the Guys' Hospital Stroke score, the sensitivity and specificity for intracranial hemorrhage were 31% and 95%, respectively; the positive predictive value was 73%. The sensitivity and specificity for ischemic stroke were 78% and 70%, respectively, and the positive predictive value was 86%. For the Siriraj Hospital Stroke score, the sensitivity and the specificity for intracranial hemorrhage were 48% and 85%, respectively; the positive predictive value was 59%. The sensitivity and specificity for ischemic stroke were 61% and 74%, respectively, and the positive predictive value was 84%. CONCLUSIONS: This validation study suggests that both clinical scores lack sufficient validity to be used in epidemiological studies for classification of stroke types and should probably not be used in the randomization of patients into treatment trials using thrombolytic or antithrombotic drugs in the absence of diagnostic information based on neuroimaging techniques.
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